Spinning apparatus



y 1957 R. ELSSNER 2,799,895

SPINNING APPARATUS Filed Nov. 15, 1952 INVENTOR.

BY 5M W1 M 2,799,895 Patented July 23, 1957 Free SPINNING APPARATUSRichard Elssner, Randerath, near Aachen, Germany, assignor, by mesneassignments, to American Enka Corporation, Enka, N. C., a corporation ofDeinware Application November 13, 1952, Serial No. 320,219 Claimspriority, application Germany N overnher 17, 1951 3 Claims. (Cl. 18-8)The present invention relates to a process and apparatus for spinningviscose, and more particularly to a process and apparatus which achievesthe spinning of viscose in such manner that there is no formation oftensioned areas on the viscose filament, which tensioned areas generallycause weakening and breaking of the filament.

in order to obtain high strength and stretching of capillary filamentsof viscose in the spinning of viscose solutions in highly concentratedsulfuric acid baths it is necessary that the capillary threads be drawnfrom the nozzle while avoiding as much as possible any tension formingon the thread. This has been accomplished in the past by very slowlydrawing the individual capillary filament from the nozzle from which itis ejected and in exactly the desired direction without deviating to anyextent. It is necessary according to this process to very carefullywatch the flowing rate of the bath. Inasmuch as the filament bundle hasa high specific weight when removed from the bath, there is a tendencyof the individual capillary filaments comprising the main filament tobreak at the moment when the filament bundle is drawn from the spinningbath.

An acid coating enveloping the individual capillary filament is drawnalong with the filament bundle. This acid coating more or less unevenlyflows back along the capillary filaments onto the surface of thespinning bath, and as it is caused to whirl, washes the individualcapillary filaments from the filament bundle. These washed apartfilaments do not break immediately; they frequently break later however,because of the untimely stretching and difference in condition betweenthese portions and the main body of the filament bundle.

It is therefore an object of the present invention to provide a processand apparatus which allows for the spinning of viscose filaments withoutany unevenly tensioned zones being formed in the filaments which mightsubsequently cause the filaments to break.

It is another object of the present invention to provide a process ofspinning viscose from highly acid spinning baths so that the acid ishomogeneously removed from the viscose filament and does not cause theformation of tensioned zones in the filament.

It is another object of the present invention to pro vide an apparatuswhich can directly spin viscose filaments from spinning baths in amanner such that the final filament is practically tension-free and hasno Weakened zones which may break in later stretching.

With the above objects in view the process of the present inventionmainly comprises withdrawing a filament of viscose from a viscosespinning bath containing sulfuric acid onto a moving transporting band,preferably of some flexible material such as rubber, so as to draw thefilament from said bath while simultaneously allowing excess sulfuricacid on the filament to run off and drain down on the transporting band,thereby avoiding the formation of any tensioned portions on the filameutdue to weighting of the same by excess acid adhering thereto; andrecovering a tension-free viscose filament.

The filament is preferably drawn off onto the transporting band moving,with the transporting band at an acute angle to the horizontal liquidlevel of the spinning bath. This acute angle, which is designated as aon the accompanying drawing, allows for the excess sulfuric acidadhering to the filament to easily drain back into the bath not onlyalong the filament itself but also along the transporting band. Thetransporting band provides a drain along which the excess liquid acidflows so that the same is homogeneously removed from the filament.

The apparatus of the present invention comprises a container adapted tohold a viscose spinning bath, which for example, may contain a highpercentage of sulfuric acid, a spinneret located in said container andadapted to eject from the spinning bath a substantially continuousfilament of viscose, and a movable transporting band, preferably of someflexible material such as rubber, adapted to receive a filament ofviscose upon ejection by said spinneret from the spinning bath andtransport the same while allowing excess liquid on the filament to runoff onto said band so as to avoid any tensioned areas forming on saidfilament and possible resultant breaking of said filament uponstretching due to the weight of excess liquid adhering to the filament.

The transporting band which may be located above the container or evendirectly over the same, preferably forms an acute angle with thehorizontal level of liquid in the spinning bath. The lower end of thetransporting band is preferably located very close to the container sothat the viscose filament travels only a very short distance beforecontacting the transporting band.

The novel features which are considered as charac teristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

The figure diagrammatically illustrates the apparatus claimed in thepresent invention.

Referring more particularly to the drawing, the freshly spun filament 1ejected from the spinneret is taken up on the continuous belt 2, shortlyafter leaving the level of the bath, indicated by the dash-line. Thecontinuous belt 2 is located on the pulleys 3 and 4. The pulley 4 is solocated with reference to pulley 3 that an acute angle is formed betweenthe belt 2 and the horizontal liquid level in the container.

It is to be noted that the arrangement according to the presentinvention provides for a degree change in direction of the filament 1 asit leaves the spinning bath and is taken up by the belt 2.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofapparatus differing from the types described above.

While the invention has been illustrated and described as embodied inapparatus and process for the spinning of viscose, it is not intended tobe limited to the details shown, since various modifications andstructural changes may be made without departing in any way from thespirit of the present invention.

The process shall be further illustrated in the following paragraphs byway of example, reference being made to the accompanying drawing:

The viscose was prepared in the conventional manner from a refinedcellulose, the alkali cellulose being subjected to a short ageingprocess only. The viscose had a cellulose content of 6.5 percent and aNaOH content of 8.0 percent. At the time of spinning the viscosity(measured by the ball fall test) amounted to 156 seconds. Theprecipitating bath contained from 900 to 980 grams of H2804- per liter,the temperature being of 20 The spinneret used had 1400 holes with adiameter of 60 microns each. 67 grams of viscose per minute were forcedthrough the spinneret by means of a conventional viscose ptunp. The band2 moved along with a speed of 125 metres per minute.-

The spinneret had been located at a level of 12 mm. below the surface ofthe precipitating bath. The distance for the filaments from thespinneret to the egress of the freshly formed thread from theprecipitating bath was of 285 mm. The diameter of the roller 3 amountedto 20 mm. and its axis was at a level of 30 mm. above the surface of theprecipitating bath. The angle of deflection for the thread at the roller3 was of 80. The axis o'f the roller 4 was spaced by 160 mm. from theaxis of the roller 3. The angle a between the surface of theprecipitating bath and the extension of the track band 2 wasof 40. i a

What is claimed as new and desired to be secured by Letters Patentis: 1. A spinning arrangement comprising, in combination, spinneretmeans for emitting a continuous filament from a spinningbath; conveyormeans for receiving a filament from said spinneret means and forconveying the filament along a given path while liquid drains from thefilament, said conveyor means extending in an upward direction forconveying the filament upwardly and having 'a bottom end spaced fromsaid spinneret means, in the direction of filament travel from saidspinneret means to said conveyor means, and located at a slightly higherelevation than said spinneret means so that the filament moves in asubstantially horizontal direction to said conveyor means .from aspinning bath having a level higher than said ,spinneret means and lowerthan said bottom end of said "conveyor means, said conveyor meansbeingsubstantially normal to the direction of filament travel and having atop end located nearer to a vertical plane passing through saidspinneret means than said bottom end of said conveyor means so that thefilament movesnearer to said plane as it is conveyed upwardly by saidconveyor means.

2. A spinning arrangement comprising, in combination, spinneret meansfor emitting a continuous filament from a spinning bath; conveyor meansfor receiving a filament from said spinneret means and for conveying thefilament along a given path while liquid drains from the filament, saidconveyor means extending in an upward direction for conveying thefilament upwardly and having a bottom end spaced from said spinneretmeans, in thedirection of filament travel from said spinneret means tosaid conveyor means, and located at a slightly higher elevation thansaid spinneret means so that the filament moves in a substantiallyhorizontal direction to said conveyor means from a spinning bath havinga level higher than said spinneret means and lower than said bottom enda of said conveyor means, said conveyor means having a top end locatednearer to a vertical plane passing through said spinneret means andbeing substantially normal to the direction of filament travel than saidbottom end of said conveyor means so that the filament moves nearer I tosaid plane as it is conveyed upwardly by said conveyor means; and aroller located between said plane and said conveyor means for guidingthe filament which leaves said conveyor means.

3. A spinning arrangement comprising, in combination, a pair of pulleysone of which is located at a higher elevation than the other and nearerto a given vertical plane; an endless band extending about said pulleysto be moved when said pulleys turn; spinneret means located in saidgiven plane at a-slightly lower elevation than said other pulley fordirecting a filament from a spinning bath to said band at a part thereofengaging said other pulley, so that the filament moves from a spinningbath whose level is lower than said other pulley and higher than saidspinneret means along a substantially horizontal path to engage and bemoved upwardly by said band.

References Cited in the file of this patent UNITED STATES PATENTSGermany Oct. 15, 1936

